A seat used in an automobile comprises a seat pad mounted on the seat frame and a skin that covers the pad. The skin has clips stitched on its fringe. The clips engage protrusions formed on the outer periphery of the seat frame. In this way, the skin is held to the seat frame. The clips take a U-shaped form, while the protrusions on the outer periphery assume an L-shaped form in cross section. More specifically, the protrusions are formed by forming slits in the frame and then raising the portions surrounded by the slits. The clips are brought into engagement with the protrusions in the manner described below. First, the skin is stretched sufficiently so that the clips may go beyond the protrusions and that the U-shaped groove in each clip may face the vertical portion of the letter "L" of the corresponding protrusion. Then, the tension applied to the skin is reduced to permit the vertical portion of the letter "L" to engage the U-shaped groove.
In recent years, a new automobile seat has been produced in which a skin and a pad have been previously combined in a unit. Clips attached to the skin on its fringe are caused to engage protrusions formed on the outer periphery of a frame. Also in this case, the fringe of the skin is pulled so that it may go beyond the protrusions. In this way, a large force is needed when the skin is mounted on the frame. Further, when the clips are caused to engage the protrusions, the skin slackens, forming creases or wrinkles.